Obscured by Clouds. The rough and ready blog of a cloud benighted biologist and amateur astronomer. Astroblog will cover my interests in astronomy, biology and Life, the Universe and Everything.

Sunday, December 11, 2016

Geminid Meteor shower, 14 December 2016

The northern horizon at 4:00 am ACDST as seen from Southern Australia
(northern Australia is similar but Gemini and the radiant is higher in
the sky) on Wednesday December 14. The Geminid radiant is marked with a starburst. Similar views
will
be seen elsewhere in Australia at the equivalent local time. (click
to embiggen).

The Geminids are a fairly reliable meteor shower but this year moonlight will significantly interfere. Normally there is also good activity either side of the peak, but this year moonlight interference means that rates in Australia will be negligible outside the peak.

The radiant doesn't rise until just
before midnight (daylight saving time) in most of Australia, so you will
still have to disturb your sleep for this one. Australians should see
a meteor every four to six minutes under dark skies in the early
morning of the 14th, between 1:00 am and 4:00 am local time. As well, the more light pollution (the closer you are to the city) , the fewer
meteors you see.

At
1.00 am in the morning AEDST (midnight, AEST) Castor (alpha Geminorum)
is about two hand-spans above the horizon and 10 hand-spans to the right
of
due north. Pollux, the other twin, is less than a hand-span to the
right
again. The radiant is just below Pollux. However, the radiant is low at
this time and you will see very few meteors until around 3:30-4 am
(daylight savings time).

Unfortunately, the Full Moon is
very near the radiant, and you will have to block it out with a
building or tree to keep some night vision, but even then you will see
only a few of the brighter meteors as the Moonlight drowns the rest out.

When looking, be sure to let your eyes adjust for at least
5 minutes so your eyes can be properly adapted to the dark. Don't look
directly at the radiant site, because the meteors will often start their
"burn" some distance from it, but around a hand-span up or to the side.
Be patient, although you should see an average of
a meteor every two minutes, a whole stretch of time can go by without
a meteor, then a whole bunch turn up one after the other.

Make
yourself comfortable, choose an observing site that has little to
obstruct the northern horizon (although you will need something to block out the Moon to preserve your night vision), have a comfortable chair to sit in (a
banana lounger is best), or blankets and pillows. A hot Thermos of
something to drink and plenty of mosquito protection will complete your
observing preparations.

You can
find predictions for your local site at the meteor flux estimator (choose 4 Geminids and date 13-14 December, don't forget to change the date to 2016). You can follow world wide Geminid counts at the IMO live Geminid site.While there are few meteors this year, Orion and the
Hyades will be visible and bright Jupiter will be above the eastern horizon. So it will be a
quite nice morning for sky watching. Keep an eye out for satellites (see Heavens Above
for predictions from your site)!Cloud cover predictions can be found at SkippySky.